High magnetic field processing of materials is of great interest, especially in the processing of certain alloys, to achieve superior properties and characteristics. Work-pieces of materials are passed in and out of high magnetic fields to affect the properties and characteristics of the processed materials. Such processes and associated apparatus are well known; see for example; U.S. Pat. No. 7,745,765 issued on Jun. 29, 2010 to Ludtka, et al. entitled “Thermal and High Magnetic Field Treatment of Materials and Associated Apparatus”; U.S. Pat. No. 7,161,124 issued on Jan. 9, 2007 to Kisner, et al. entitled “Thermal and High Magnetic Field Treatment of Materials and Associated Apparatus”; and U.S. Pat. No. 6,773,513 issued on Aug. 10, 2004 to Kisner, et al. entitled “Method for Residual Stress Relief and Retained Austenite Destabilization”.
A high magnetic field environment generally comprises a uniform maximum magnetic field region surrounded by a gradient magnetic field region. When a ferromagnetic material is either inserted into or removed from a high magnetic field region, the magnetic field gradient region imparts a significant force which must be overcome in order to move the material into or out of position. For example, low carbon steel in a 9 Tesla superconducting magnet with a gradient scale length of ⅙ meter is generally subject to an attractive magnetic force of 280 lbs. per cubic inch of steel. Therefore, to insert and/or remove a relatively large work-piece into a high magnetic field region such as a thermomagnetic processing device, the work-piece can experience forces on the order of hundreds to thousands of pounds. Such resistive force makes work-piece insertion and/or removal a potentially difficult task.
The high resistive force issue is a negative driving force for carriage (work-piece handling and/or transport system) design that requires very large and cumbersome framework to overcome the high forces that are imparted upon the work-piece during insertion and removal processes. It is desirable to mitigate such resistive forces in a magnetic field environment to facilitate ease of work-piece loading, in many cases for magnets having as little as 1 Tesla.